Hepatitis B virus genotype G epidemiology and co-infection with genotype A in Canada

Abstract

Hepatitis B virus (HBV) genotype G (HBV/G) is an unusual variant, and little is known about its epidemiology and natural history, particularly the requirement for a co-infecting HBV genotype and their relationship during infection. This study investigated the quasispecies nature of coinfecting genotypes in 39 samples collected over a 6 year period from 13 HBV/G-infected patients. HBV/G infections were found to occur predominantly in males (92 %) and were primarily associated with male homosexual sex (67 %). All patients were infected with HBV/G and HBV/A, or a recombinant HBV/A/G strain. Co-infecting genotypic prevalence was often observed to fluctuate over time, with periods of HBV/G monoinfection in some patients. The average sequence divergence among Canadian HBV/G strains was 1.57±0.62 %. Thus, all HBV/G infections in Canada occur in the context of co-infection or recombination with HBV/A, and strains display increased sequence divergence compared with all known HBV/G sequences described to date.

Identification of novel recombinants of hepatitis B virus genotypes F and G in human immunodeficiency virus-positive patients from Argentina and Brazil

“…HBV/G was described by Stuyver et al (2000) and, despite low prevalence, seems ubiquitous, as it has been reported in Europe (Lacombe et al, 2006;Vieth et al, 2002), the Americas (Alvarado-Esquivel et al, 2006;Alvarado Mora et al, 2011;Bottecchia et al, 2008;Chu et al, 2003;Osiowy et al, 2008), Asia (Shibayama et al, 2005;Toan et al, 2006) and Africa (Olinger et al, 2006;Toan et al, 2006). HBV/G is frequently reported in patients infected with human immunodeficiency virus (HIV) (Dao et al, 2011;Zehender et al, 2003), particularly in men who have sex with men (MSM) (Bottecchia et al, 2008;Osiowy et al, 2008). Patients co-infected with HBV/ G and HIV have an increased risk of liver fibrosis compared with those infected with other HBV genotypes Downloaded from www.microbiologyresearch.org by IP: 18.236.120.13…”

“…HBV/G is unusual in several aspects: it has a 36 bp insertion at the beginning of the core gene and two stop codons in the precore region (codons 2 and 28), preventing expression of HBeAg (Kato et al, 2002). Moreover, it almost exclusively co-infects with another HBV genotype, usually HBV/A (Kato et al, 2002;Osiowy et al, 2008), but HBV/C (Suwannakarn et al, 2005), HBV/F (Fallot et al, 2012) and HBV/H (Sánchez et al, 2007) have also been reported. Recombination between HBV/G and the co-infecting genotype has been observed, especially in patients with HIV (Fallot et al, 2012;Martin et al, 2011;Osiowy et al, 2008).…”

“…Moreover, it almost exclusively co-infects with another HBV genotype, usually HBV/A (Kato et al, 2002;Osiowy et al, 2008), but HBV/C (Suwannakarn et al, 2005), HBV/F (Fallot et al, 2012) and HBV/H (Sánchez et al, 2007) have also been reported. Recombination between HBV/G and the co-infecting genotype has been observed, especially in patients with HIV (Fallot et al, 2012;Martin et al, 2011;Osiowy et al, 2008). Recombination is an important element of HBV genetic variability and may have clinical implications (Fallot et al, 2012;Kay & Zoulim, 2007;Simmonds & Midgley, 2005 .…”

Molecular Evolution of Hepatitis Viruses

“…This genotype is might be found more frequently in co-infection with HIV (Dao et al, 2011). Alternatively, HBV genotype G is found frequently infecting men who have sex with men (MSM) (Bottechia et al, 2008;Osiowy et al, 2008;Sanchez et al, 2007). The core variability displayed by HBV genotype G (a 12 amino acid insertion at the N-terminal end) has been shown frecently that migh be affecting the ability of assembly and secretion of the viral particle (Cotelesage et al, 2011), which supports the assumption for the need of a coinfecting strain for an efficient replication of this genotype.…”

Hepatitis B virus infection: An insight into infection outcomes and recent treatment options

“…The prevalence of chronic HBV infection is inversely correlated with age at the time of infection, hence, [90 % perinatal infections progress to chronic HBV infection. Based on a long-term study conducted in Taiwan, [25 % of HBV infections in preschool children and \4 % of infections in adolescents progressed to chronicity [4,5].…”